(1) Field of the Invention
This invention relates to slurry seal emulsions. More particularly, it relates to novel emulsifiers for solventless and solvent containing, mixing grade, oil-in-water anionic bituminous emulsions, which emulsifiers are derived from the reaction products of alkyl phenols, aldehydes and polyamines, post-reacted with acrylic acid.
(2) Description of related art
In paving operations, three main practices are employed to achieve thorough mixing of bitumen and aggregate:
(1) mixing of free flowing heated asphalt (asphalt cement) with pre-dried aggregate; PA1 (2) mixing pre-dried aggregate with asphalt diluted with a hydrocarbon solvent (cutback asphalt, cutter stock) at ambient temperatures; and PA1 (3) mixing aggregate with asphalt emulsions, e.g., oil-in-water emulsions, obtained by vigorous agitation of asphalt and water in the presence of an emulsifying agent.
Because of increasing cost in energy and hydrocarbon solvent and because of environmental concerns, the use of emulsified asphalt is increasing.
Conventionally, emulsion slurry seals are formulated from mineral aggregate which is a fine stone aggregate and/or mineral filler and a mixing-grade, quick-setting or slow-setting emulsion containing bituminous residue (usually asphalt), and water to attain slurry consistency. Usually, densely-graded aggregates, such as granite screening, limestone screening, dolomite screening and blast furnace slag, are combined with bituminous emulsions to produce slurry seal compositions.
When a slurry seal is used in paving and road maintenance, the mixture of emulsified bituminous material and fine-grained aggregate is held in suitable suspension until applied to the road surface. The slurry seal emulsion is of an oil-in-water type.
Depending on the emulsifier used to achieve an emulsion, anionic or cationic emulsions are obtained. In anionic emulsions, asphalt droplets are negatively charged; in cationic emulsions, the asphalt droplets bear positive charges.
In a bituminous emulsion formulated using anionic emulsifiers the bituminous material is deposited from the emulsion on calcareous aggregate due to the attraction of polar charges between the negatively charged bituminous droplets and positively charged aggregate surfaces.
Anionic bituminous emulsions are taught by Wright and Mertens in U.S. Pat. No. 3,062,829 to be prepared by employing alkali emulsifier and polyamide additives which are the condensation products of dilinoleic acid and polyalkylene polyamines. Lignin amines are taught as anionic emulsifiers in U.S. Pat. No. 3,123,569 to Borgfeldt. Also, Moorer, in U.S. Pat. No. 3,956,002, teaches an anionic emulsifier consisting of an oxygenated alkali lignin, an ethylene oxide adduct of alkylphenol, and up to 10% by weight of sodium borate; and, in U.S. Pat. No. 4,088,505, he teaches an anionic emulsifier consisting of an alkali metal salt of an alkali lignin, an ethylene oxide adduct of alkylphenol and water. In addition, Montgomery and Pitchford teach the alkali metal salts of complex polynuclear aromatic polycarboxylic acids as anionic asphalt emulsifiers in U.S. Pat. No. 3,344,082. Heinz, in U.S. Pat. No. 3,006,860, similarly employs alkali metal soaps of higher fatty acids as those found in tall oil.
Ferm, in U.S. Pat. No. 3,740,344, teaches the preparation of quick-setting anionic slurry seal compositions by applying a combination of anionic emulsifiers such as aryl alkyl sulfonates and condensation products of ethylene oxide with alkylated phenols, with fatty alcohols, with mono-esters of fatty acids with glycerol or sorbitol or long chain fatty acids. H. G. Schreuders, in U.S. Pat. No. 3,615,796, teaches the use of petroleum sulfonates as quick-setting anionic slurry seal emulsifiers. A combination of sodium lignate or lignosulfonate and saponified rosin or tall oil is described in U.S. Pat. No. 3,594,201 by Sommer and Evans. Also, Conn, in U.S. Pat. No. 3,350,321, describes the use of alkyl or alkoxy-alkyl phosphoric acids as emulsifiers for asphalts.
The use of tallow quaternary ammonium salts and tallow diquaternary diammonium salts for making emulsions suitable for slurry seal in solventless applications is described in U.S. Pat. No. 3,764,359 to Dybalski.
The uses of acidified reaction products of certain polycarboxylic acids, anhydrides, sulfonated fatty acids and epoxidized glycerides with certain polyamines as emulsifiers yielding asphalt emulsions which can mixed with fine grained aggregate to give workable aggregate/emulsion mixes are disclosed in U.S. Pat. No. 4,447,269 to Schreuders et al., U.S. Pat. Nos. 4,450,011, 4,547,224, 4,462,890 to Schilling et al., U.S. Pat. Nos. 4,464,286, 4,561,901, 4,597,799 to Schilling, and U.S. Pat. No. 4,676,927 to Schilling et al. The use of a quaternary amine obtained by reacting epichlorohydrin, trimethylamine and nonylphenol for solventless mixes is disclosed in U.S. Pat. No. 3,957,524 to Doughty.
Quick-setting bituminous emulsion compositions wherein amine and alkanolamine salts of alkylbenzenesulfonic acid are used as emulsifiers are disclosed in the U.S. Pat. No. 4,657,595 to Russell.
The general object of this invention is to provide novel versatile anionic emulsifiers for solventless and solvent containing, rapid setting, mixing grade, oil-in-water bituminous emulsions.
Another object is to provide an anionic bituminous emulsion for mixing with aggregates whose coating characteristics and set time can be varied.